Since the development of dense-graded aggregate base in Kentucky about 1952, there have been various conjectures about "auto-cementations" or "setting" of these materials when compacted and cured. In some cases, particularly when the material was limestone, they have developed rather surprising strengths, in the field as well as in the laboratory. Such displays of strength seem to be directly associated with curing (slow drying) and the possibility of re-deposition of small amounts of dissolved calcium carbonate as cement. If this is so, it might be surmised that bases which have not been "fixed" by curing and drying before surfacing may never acquire strength by virtue of auto-cementation, or may loose it on re-wetting. It may be surmised, likewise, that unless auto-cementation occurs, the supporting ability of the base must be governed by the binding power of whatever moisture is present and by virtue of physical confinement. Thus, the idea of deliberately introducing cement is quite logical if inherent strength is to be assured.

Report Date


Report Number

No. 140

Digital Object Identifier



Presented to Kentucky Department of Highways, Research Committee, February 16, 1959.